One piece plastic expansion fastener



Nov. 7, 1967 s. B. TOPF 3,350,!976

ONE PIECE PLASTIC EXPANSION FASTEN-ER Filed Oct, 18, 1965 ml l6 I :2 E 22 .1 B

SAIVI BTOFF United States Patent 3,350,976 ONE PIECE PLASTIC EXPANSION FASTENER Sam B. Topf, Coral Gables, Fla, assignor of one-half to Louis Rolnick, Miami Beach, Fia. Filed Get. 18, 1965, Ser. No. 496,950 2 Claims. (Cl. 85-37) ABSTRACT OF THE DISCLOSURE A fastening device having a pair of legs of bendable material extending axially through its mounting bore in parallel spaced relation and an elongated axially extending member having its inner portion split to form a pair of further legs, their inner ends joined to the inner ends of said first legs, a cap on the outer end of each of said first legs and a head on the outer end of said elongated member adapted to be forced inwardly to a locked position between said caps so as to hold the inner ends of said first legs bent and clamped outwardly against the inner edge of the bore.

This invention relates generally to fastening devices and is more particularly directed to an anchoring device.

A principal object of the present invention is to provide an anchoring device that is of unitary construction requiring no pins, nails, screws or outside means for locking the anchor in place.

Another object of the present invention is to provide an anchoring device made preferably of plastic whose locking means consists of a member that extends above the head of the anchor whereby upon forcing the lock ing means inwardly in engagement with the head of the anchor, the latter will be expanded and locked in place.

A further object of the present invention is to provide an anchoring device which is used to fasten members to gether or hang articles on a wall and may be removed readily and reused as often as desired.

A still further object of the present invention is to provide an anchoring device which locks into position positively by overlapping its ends over the sides of the opening rather than just by expanding and fitting tightly in the opening.

A still further object of the present invention is to provide an anchoring device that is simple in construction, inexpensive in cost of production, most effective as an anchoring device and which requires no more tools than a hammer to lock the device in place and a pair of pliers to remove same.

With these and other objects in view, the invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawing forming a part of this specification, with the understanding, however, that the invention is not confined to any strict conformity with the showing of the drawing but may be changed or modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawing:

FIGURE 1 is a perspective view of an anchor constructed in accordance with my invention.

FIGURE 2 is a side elevational view.

FIGURE 3 is a similar view with the anchor rotated 90 degrees from the position shown by FIGURE 2.

FIGURE 4 is a view showing the anchor in position for locking certain members together.

FIGURE 5 is a similar view showing the anchor in its locked position.

form a unitary device.

The body member B consists of a pair of symmetrically disposed leg portions whose outside surfaces are arcuate so as to fit in a cylindrical opening 20 such as that shown in FIGURES 4 and 5. The inside surface of the leg portions 11 are flat and spaced as at 17 from the fastening member F except for the lower ends which are joined as explained in detail hereinafter.

Mounted on the upper ends of the leg portions 11 are cap portions 12 forming segments whose outer surface is arcuate forming an arc of greater radius than that of the outer surface of the leg portion 11 while the inner surface is flat. The inner surface of the cap portion 12 forms a shoulder or abutment as at 14 by virtue of an obliquely disposed fiat surface 16 joining a vertically dis posed surface 15.

The shoulder structure 14, 15 and 16 is engaged by a head portion 21 which is mounted on the free end of a main body portion 22 of the fastening means F. The head portion is normally positioned above the cap portions 12 as the body portion 22 of the fastener F is longer than the leg portions 11 of the body member B. Bevelled portions 23 are provided on the head portion 21 for engagement with the shoulder 16 in the operation of locking the anchor 10.

The body portion 22 of the fastening member F is split as at 24 to form a pair of legs 25 whose free ends are joined to the free ends of the leg portions 11 forming the ends 26 of the fastening device 10. The legs 11 and 25 are serrated along their outer surfaces as at 27 for the purpose of permitting the legs 11 and 25 to bend more readily and also to engage and grip the inner edge portion of the opening 20 when the anchor 16 is in its locked position as best shown by FIGURE 5.

When it is desired to utilize the anchor 10 in securing two members 29 and 30 together, the anchor 10 is inserted in the opening 20 in the members 29 and 30- and forced inwardly until the cap portions: 12 engage the outer surface of the member 29. Then the body member 22 is forced to slide inwardly of the anchor 10 either by exerting a downward force on the head portion 21 or by a blow as by a hammer. As the body member 22 slides downwardly along the legs 11, 11, the end portions 26, 26 will begin to curl outwardly in a direction away from each other and the serrations 27 on the legs 11 engage the circumferential edge portion of the opening 20. When the head portion 21 engages the outer surface of the member 29, the bevelled surfaces 23 will have been engaged by the shoulder means 14, 16 to lock the fastening member F and body member B together as shown by FIGURE 5. The side walls of the opening 20 in the members 29 and 30 prevent the legs 11 and 22 from spreading apart and thereby prevent the head portion 21 from sliding upwardly past the shoulders 14, 16. However, if it is desired to remove the anchor 10 from the members 29, 30, a tool such as a pair of pliers are used to grip the head portion 21 and bodily pulled outwardly of the cap portions 12 whereby the beveled portions 23 are compelled to slide past the shoulders 14, 16. A continued upward pull on the head portion 21 will cause the body portion 22 to slide upwardly and the legs 11, 11 and 22, 22 to assume the position shown by FIGURE 4 at which time the anchor 10 is readily removed from the opening 20. The anchor 10 may be used over and over again as long as the legs 11, 11 and 22, 22 remain secured together at their ends.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A reusable anchor of stiff resilient plastic material for fastening a plurality of members together having a longitudinally disposed axis comprising a pair of leg portions mounted in spaced and substantially parallel relation about said axis and received by a bore in said members, a cap portion mounted on the outer end of each of said leg portions, said cap portions being positioned on each side of said axis for engaging ;the outer surface of the outermost one of said members, an elongated member disposed along said axis spaced between said leg portions and terminating at its outer end in a head portion normally above said cap portions when the anchor is not in use, said elongated member normally having an axially disposed slot extending from the inner end of said elongated member and terminating intermediate said ends, said slot forming a pair of further leg portions in normally spaced parallel relation between said first leg portions, the inner end of each of said first leg portions being joined to the inner end of the adjacent further leg portion, shoulder means formed on said cap portions, and bevelled edges formed on the side edges of said head portion adapted to cooperatively engage said shoulders for locking said head portion when said head portion is received between said cap portions, to said cap portions after said elongated member has been forced slidably inwardly with relation to said first main leg portions while mounted in said bore, until the bevelled edges of said head portion have been engaged by the shoulder means on said cap portions and said leg portions being adapted to be bent outwardly along their full length as a result of the force applied to slide said elongated member inwardly, into intimate relation to the opposite sides of said bore and around the inner edges thereof, and to return to their original axially extended form upon application of force to said head of said elongated member for sliding it out to its normally extended position.

2. An anchor as defined in claim 1, the inner portions of said leg portions having serrations in their outer surfaces to facilitate their bending during installation of the anchor and during its removal for reuse, as well as to provide good gripping surfaces against said bored members.

References Cited UNITED STATES PATENTS 1,031,431 7/1912 Dunn -37 2,344,717 3/1944 Mills et al 8582 2,501,701 3/1950 Tinnerman 85-37 3,074,134 1/1963 Buechler 2473 3,114,949 12/1963 Meyer 85-82 3,130,822 4/1964 Meyer 2473 3,279,643 10/1966 Amesbury 85--82 FOREIGN PATENTS 1,373,541 8/1964 France.

718,099 3/1942 Germany.

MARION PARSONS, JR., Primary Examiner,

CARL W. TOMLIN, Examiner. 

1. A REUSABLE ANCHOR OF STIFF RESILIENT PLASTIC MATERIAL FOR FASTENING A PLURALITY OF MEMBERS TOGETHER HAVING A LONGITUDINALLY DISPOSED AXIS COMPRISING A PAIR OF LEG PORTIONS MOUNTED IN SPACED AND SUBSTANTIALLY PARALLEL RELATION ABOUT SAID AXIS AND RECEIVED BY A BORE IN SAID MEMBERS, A CAP PORTION MOUNTED ON THE OUTER END OF EACH OF SAID LEG PORTIONS, SAID CAP PORTIONS BEING POSITIONED ON EACH SIDE OF SAID AXIS FOR ENGAGING THE OUTER SURFACE OF THE OUTERMOST ONE OF SAID MEMBERS, AN ELONGATED MEMBER DISPOSED ALONG SAID AXIS SPACED BETWEEN SAID LEG PORTIONS AND TERMINATING AT ITS OUTER END IN A HEAD PORTION NORMALLY ABOVE SAID CAP PORTIONS WHEN THE ANCHOR IS NOT IN USE, SAID ELONGATED MEMBER NORMALLY HAVING AN AXIALLY DISPOSED SLOT EXTENDING FROM THE INNER END OF SAID ELONGATED MEMBER AND TERMINATING INTERMEDIATE SAID ENDS, SAID SLOT FORMING A PAIR OF FURTHER LEG PORTIONS IN NORMALLY SPACED PARALLEL RELATION BETWEEN SAID FIRST LEG PORTIONS, THE INNER END OF EACH OF SAID FIRST LEG PORTIONS BEING JOINED TO THE INNER END OF THE ADJACENT FURTHER LEG PORTION, SHOULDER MEANS FORMED ON SAID CAP PORTIONS, AND BEVELLED EDGES FORMED ON THE SIDE EDGES OF SAID HEAD PORTION ADAPTED TO COOPERATIVELY ENGAGE SAID SHOULDERS FOR LOCKING SAID HEAD PORTION WHEN SAID HEAD PORTION IS RECEIVED BETWEEN SAID CAP PORTIONS, TO SAID CAP PORTIONS AFTER SAID ELONGATED MEMBER HAS BEEN FORCED SLIDABLY INWARDLY WITH RELATION TO SAID FIRST MAIN LEG PORTIONS WHILE MOUNTED IN SAID BORE, UNTIL THE BEVELLED EDGES OF SAID HEAD PORTION HAVE BEEN ENGAGED BY THE SHOULDER MEANS ON SAID CAP PORTIONS AND SAID LEG PORTIONS BEING ADAPTED TO BE BENT OUTWARDLY ALONG THEIR FULL LENGTH AS A RESULT OF THE FORCE APPLIED TO SLIDE SAID ELONGATED MEMBER INWARDLY, INTO INTIMATE RELATION TO THE OPPOSITE SIDES OF SAID BORE AND AROUND THE INNER EDGES THEREOF, AND TO RETURN TO THEIR ORIGINAL AXIALLY EXTENDED FORM UPON APPLICATION OF FORCE TO SAID HEAD OF SAID ELONGATED MEMBER FOR SLIDING IT OUT TO ITS NORMALLY EXTENDED POSITION. 